Impact fuze



Sept. l2, 1961 R. APoTHELoz ETAL 2,999,461

IMPACT FUZE was* "lll/ Rober APoTHLoZ Mexx HUBER INVENTORS 11ml WMZ Alt 2 Sheets-Sheet 2 IMPACT FUZE R. APOTHELOZ ETAL Sept. 12, 1961 Filed March 25. 1959 Hmx HUBER B INVENTORS TrrMAH-I 2,999,461 IMPACT FUZE Y Robert Apotheloz, Wallisellen, Zurich, and Max Huber, Zurich, Switzerland, assignors to Machine Tool Works Oerlikon, Administration Company, Zurich-Oerlikon, Switzerland, a company of Switzerland Filed Mar. 23, 1959, Ser. No. 801,226 Claims priority, application Switzerland Mar. 28, 1958 3 Claims. (Cl. 102-75) of the kind referred to in which the delayed, action` device requires but little space.

It is yet another object of the invention to provide a fuze of the kind referred to which is suitable for nonspun projectiles, for example for those tired from a mine projector.

atent f .l

With these and other objects in view which will become l apparent later from this specification and the accompanying drawings, we provide an impact fuze for projectiles, comprising in combination: a fuze body, a striker pin slidably mounted in a longitudinal bore of the said fuze body, locking bodies in the transport condition of the fuze engaging into an annular groove within the said bore bounded in front by a chamfered surface integral with said fuze body, two inertia sleeves arranged longitudinally slidable in alignment with one another in said bore, the rear one of said two inertia sleeves abutting at its rear end said fuze body, and a spring interposed between said rear inertia sleeve and said striker pin, said two inertia sleeves when-contacting one another securing said locking bodies in their aforesaid transport position and releasing said striker pin. y

Preferably said impact fuze comprises in addition: a carrier slide movable transversely ofthe fuze axis from a transport position to a cocked position, a detonator located in a bore of said carrier slide, said bore in the transport position being offset from and in the, cocked position being in alignment with said striker pin, said carrier slide having a groove parallel to the direction of its movement, the forward one of the said two inertia sleeves being capable of engaging into said groove in the forward position of said forward inertia sleeve.

These and other features of our invention will be clearly understood from the following description of a preferred embodiment thereof given by way of example with reference to the accompanying drawings, in which:

FIG. l shows the fuze in the transport position in a longitudinal section on the line I-I of FIG. 2,

FIG. la shows the switch-over pin in the position for FIGS. 6 to l0 show various functional positions of the I delayed action device on a larger scale, namely:

FIG. 6 the transport position, in section on the line VI-VI of FIG. 2,

ice

FIG. 10 the position for dud action of thefuze, n'

FIGS. 9 and 10 being broken off. l

According to FIG. l the fuze casing 1 is screwed to the fuze head 2 and carries at its rear end the booster 10.

In the fuze head a cup 3 xedly connected to the instantaneous central vstriker pin 4l is mounted slidably. A spring 5 abuts the fuze head 2 and the cup 3 in such a manner that the latter is always biased outwardly. A hood 6 made of plastic material put on the fuze head 2 serves as a seal, and is so resilient thatit resumes its normal shape'even after being deformed.` YThe bearing body 7 inserted in the Afuze casingY is provided with a rectangular groove 8 extending transversely of the fuze axis (FIG. 4) wherein a prismatc slide 9 is housed. The slide 9 has two bores rparallel to the fuze axis, one of which contains a detonator 11 to be pierced by the instantaneous striker pin 4, and the other contains a detonator 13 to be pierced from the rear (FIG. 5). These bores run parallel to the longitudinal direction of the slide and are laterally odset from one another (FIG. 2). The axis of a further, blind bore 14 coincides'with rthe fuze axis in the transport position of the slide. In the rear face of the slide a groove 9a is machined which ends i over arrested by balls 20, which engage into an annular Y groove 21 of the fuze casing 1 and are retained by a locking pin 18 slidably mounted inthe interior of the lockingsleeve. A spring 19 abutting the lockingfsleeve 16 from within biases this locking pin into its locking position. 1

The slide 9 is laterally provided with a rack 22 in mesh with a gear pinion 23 inserted in the bearing body Tand in driving connection through the gearing 25 (not illustrated in detail) with an oscillatory body. This gearing together with the oscillatory body forms an escapement, which delays the shifting of the slide from its transport position into the cocked position, whereby a certain trajectory safety distance of the fuze is established.

In a longitudinal central bore of the fuze body 1 a detonating train 26 is inserted which reaches from the rear edge of the slide 9 right to the booster 10, and in a.

wider bore 27 parallel to the same a device for delayed detonation is contained (FIGS. 5 and 6). A cylindrical rod 34 reaches into the bore 27 from the bottom thereof to which it is tixed. Its forward end is provided with a circumferential annular groove 35, which is bounded in front by a charnfered surface 36. An inertia sleeve 37, which is movable in the said bore, is pushed over the rod 34 and rests in the transport position on the foot thereof. Between the shoulder 38 of the bore of said sleeve 37 and the rear end'of the forward striking pin"28 a striker spring 39 is inserted. 't n Y n The forwardfend of the rod 34 reaches into the bore V29 of the striker pin 28.i The latter is coupled with the rod 34 and retainedby safety balls 40 contained in` its radial bores 30, which balls are forced by the bias of the spring 39 against the chamfered surface 36 of the said rod 34 which is connected to the fuze body 1. At the same time the balls 40 are also forced against the inner Y the bore of which yhas the ysame diameter as the bore of t-he forward part of the rst inertia sleeve 37, abuts with its chamfered rear end face 42 the forward end face of the said first inertia sleeve 37. The forward reduced part 43 of the said sleeve 41 reaches under the guide track of the slide 9.

The switch-over pin 31 (FIG. 4), inserted perpendicular to the fuze axis into the fuze body 1 and bearing body 7, may be turned by means of a notch 32 provided on its end face into two different positions marked on the circumference of the fuze casing. On the other end of the said switch-over pin 31 the latter is provided with a bore 33 co-axially to its longitudinal axis, into which bore the instantaneous striker pin 4 dips in its transport position. In that position of the switch-over pin 31, which is for instantaneous detonation, the striker pin 4 can pass across the said pin in accordance with FIG. 1. In the other position (offset 90 from the aforesaid position) into which the pin 31 is turned for delayed detonation, the passage for the instantaneous striker pin 4 is, on the other hand, blocked as shown in FIGS. la and 5.

From this arrangement results the following manner of operation of the fuze:

In the position of the fuze as illustrated in FIG. l the slide 9 is arrested in its transport position by the locking sleeve 16. When firing the projectile, the locking action of the locking sleeve 16 is abolished, and by its rearward movement the latter releases the slide 9. When the switch-over pin 31 has been turned into the instantaneous detonation position, the slide 9 remains, however, yet secured during the acceleration period of the projectile, since simultaneously with the locking sleeve 16 the instantaneous striker pin 4 moves rearward against the bias of the spring 5, and penetrates across the switch-over pin 31 into the blind bore 14 of the slide 9. After the projectile has emerged from the barrel of the Weapon, the air drag has a decelerating effect on it so that the instantaneous striker pin 4 is again biased towards its transport position and releases the slide 9. The locking sleeve 16 remains arrested in the redrawn position, in that the locking pin 18 moving forward forces the balls 20 outward, so that the same jam on the annular shoulder 24 of the fuze casing 1. Under the bias of the spring the slide 9 then slides at a rate corresponding to the trajectory safety distance desired into the cocked position, in which the axis of the detonator 11 coincides with the axis of the instantaneous forward striking pin 4 and of the detonating train 26, while the detonator 13 comes to lie coaxially above the striker pin 28 (FIGS. 3 and 5). Upon impact on the target the striker pin 4 is forced into the detonator 11 which through the detonating train 26 ignites the booster 10, and the latter detonates the proper explosive charge of the projectile (not shown in the drawings).

When the switch-over pin 31 is adjusted for delayed detonation the path towards the slide 9 is blocked for the instantaneous striker pin 4, which is thrown back when firing. After being released by the locking sleeve 16, the slide 9 is moved in the manner described hereinabove into the cocked position. Upon impact of the projectile the two inertia sleeves 37, 41 are then thrown forward by inertia in spite of the braking force applied to them by the frictional engagement with the safety balls 40, until the shoulder 44 of the inertia sleeve 41 abuts the rear face of the slid 9 (FIG. 7). By this movement of the inertia sleeve 37 the striker spring 39 is further loaded.

When the deceleration of the projectile and accordingly of the fuze has dropped to a low value, the striker spring 39 can move the inertia sleeve 37 rearward so that the balls 40 emerge from the annular groove 35 under the bias of the chamfered surfaces 36 of the rod 34 and enter into the space now forming between the two inertia sleeves 37, 41- (FIG. 8). The pin 2.3 is thereby released, and is thrown forward by the action of the striker spring 39. The balls 4,0 are guided; inward by the chamfered rear face 42 of the inertia sleeve 41 into the bore lS29 uof the striker pin 28, so that the same then moves unhampered on a cleared way up to the shoulder of the inertia sleeve 41 and penetrates through the bore 12 into the detonator 13 (FIG. 9). In the cocked position of the slide 9 the detonator 13 is in spatial-communication with the detonator 11 through the groove 7a machined in the bearing body 7, and ignites the detonator 11 by the impinging flame, whereby the explosive charge is detonated in the usual manner.

When the projectile is decelerated after the firing and is simultaneously also deflected from its trajectory, for example by touching upon the boughs of trees or the like, a short shot or misiiring may result, which upon impact would endanger the tiring troops by a detonation. A further advantageous feature of the device illustrated for delaying the detonation consists in that, provided the deceleration occurs within the trajectors safety distance, it has the effect of not cooking the fuze, so that the projectile hits as a dud. This is attained by an additional functioning of the device described briefly as follows:

By the aforesaid unintentional deceleration of the projectile the inertia sleeves 37 and 41 are thrown forward by inertia, the reduced portion 43 ofthe sleeve 41 engaging into the groove 9a of the slide 9 while the latter is moving towards the cocked position. The movement of this inertia sleeve is limited by the bottom of this groove 9a, and the slide 9 is secured in an intermediate position (FIG. l0) by the contact, with the end face 9b of the groove, of the part 43 of the inertia sleeve 41, which is arrested in this position by the balls 4t). In this position none of the two detonators 11, 13 lies co-axially with the associated striker pin 4 or 28, respectively. Upon impact of the projectile these detonators cannot consequently be pierced so that the projectile does not detonate.

While we have herein described and illustrated in the accompanying drawings what may be considered a typical and particularly useful embodiment of our said invention, we wish it to be understood, that we do not limit ourselves to the particular details and dimensions described and illustrated; for obvious modifications will occur to a person skilled in the art.

What we claim as our invention and desire to secure by Letters Patent, is:

1. A delay impact fuze for projectiles comprising a fuze casing having a longitudinally extending bore therein, a slide transversely slidable in said casing, means for moving said slide from a safety position to a ring position, a forward striking pin located in said bore, a detonator which is aligned with said pin when said slide is in firing position, a first inertia sleeve slidably mounted in said bore, a second inertia sleeve also slidably mounted in said bore behind said rst sleeve and normally abutting said rst sleeve, a rod fixed to said casing located within said sleeves having a circumferential` groove at the upper part thereof, an extension upon said pin having a bore accommodating the top portion of said rod, said extension having recesses extending transversely thereof, balls in said recesses cooperating with said circumferential groove in said rod and with said `first and said second inertia sleeve normally locking said pin, a striker spring cooperating with said second inertia sleeve and said extension upon said pin, said second inertia sleeve compressing said spring uponv impact against said pin and moving said first inertia sleeve into abutment with said slide wherebyV said striker spring operative upon deceleration separates said sleeves thereby releasing said balls from said rod and movingsaid balls along said bore of said extension and said pin to detonating position.

2. A delay impact, fuze for projectiles comprising a fuze casing having a longitudinally extending bore there` in, a slide transversely slidable in said casing, means for moving said slide from a safety position toa tiring position, a forward striking pin located in` said bore, a detonator which is aligned with said pinwhen said slider is in ring position, a Erst inertia sleeve slidably mounted in said bore having an engagement means, a second inertia sleeve also slidably mounted in said bore, means for locking said pin, a striker spring cooperating with said second inertia sleeve and said pin, said second inertia sleeve compressing said striker spring upon impact against said pin and moving said iirst inertia sleeve into abutment with said slide, said striker spring being operative upon deceleration unlocking said locking means by means of said second inertia slide for the forward movement of said pin to detonate said detonator, said slide having a straight groove at its rear end extending parallel to its direction of movement and terminating at a point prior to ring position of said slide into which said engagement means of said lrst sleeve may project and thereby prevent said slide from reaching firing position.

3. A delay impact fuze for projectiles comprising a fuze casing having a longitudinally extending bore therein, a slide transversely slidable -in said casing, means for moving said slide from a safety position to a ring position, a forward striking pin located in said bore, a detonator which is aligned with said pin when said slide is in tiring position, a rst inertia sleeve slidably mounted in said bore having an engagement means, a second inertia sleeve also slidably mounted in said bore behind said first sleeve and normally abutting said trst sleeve, a rod xed to said casing located within said sleeves having a circumferential groove at the upper part thereof, an extension upon said pin having a bore accommodating the top portion ofy said rod, said'extension having recesses extending transversely thereof, balls in said recesses cooperating with said circumferential groove in said rod and with said rst and second inertia sleeve normally locking said pin, a striker spring cooperating with said second inertia sleeve and said extension upon said pin, said second inertia sleeve compressing said spring upon impact against said pin and moving said iirst inertia sleeve into abutment with said slide wherebysaid striker References Cited in the Ele of this patent UNITED STATES PATENTS 1,545,139 Greenwell July 7, 1925 2,651,993 Berzof Sept. 15, 1953 2,685,253 Apotheloz Aug. 3, 1954 2,831,431 Stevenson Apr. 22, 1958 2,872,868 Donahue Feb. 10, 1959 2,882,825 Losfeld Apr. 21, 1959 

